The present disclosure provides a system and method for inspecting an aircraft. An X-ray/Gamma ray radiation source and a detector are located at above and below a fuselage of an aircraft, respectively. The X-ray/Gamma ray radiation source emits a beam of radiation[ ], wherein the X-ray/Gamma ray radiation[ ] passes through the aircraft to be inspected. The detector receives and converts the beam of X-ray/Gamma ray radiation[ ] that has passed through the aircraft to an output signal, and the system generates a vertical transmission image in real time.